Mips MC object code emission improvements:

Mips MC object code emission improvements:

"With this patch we can now generate runnable Mips code through LLVM
direct object emission. We have run numerous simple programs, both C
and C++ and with -O0 and -O3 from the output. The code is not production
ready, but quite useful for experimentation." Patch and message by
Jack Carter

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144414 91177308-0d34-0410-b5e6-96231b3b80d8